Does transvaginal ultrasound at 13-15 weeks improve anatomic survey completion rates in obese gravidas?

First-Trimester Ultrasound Screening in Routine Obstetric Practice

Technologic advances and ultrasonographer-physician experience in fetal imaging have led to significant improvements in our ability to distinguish between normal and abnormal fetal structural development in the latter part of the first trimester. As a critical component of pregnancy care, assessment of fetal anatomy at the end of the first trimester with a standardized imaging protocol should be offered to all pregnant patients regardless of aneuploidy screening results because it has been demonstrated to identify approximately half of fetal structural malformations. Early identification of abnormalities allows focused genetic counseling, timely diagnostic testing, and subspecialist consultation. In addition, a normal ultrasound examination result offers some degree of reassurance to most patients. Use of cell-free DNA alone for aneuploidy screening while foregoing an accompanying early anatomic evaluation of the fetus will result in many anomalies that are typically detected in the first trimester not being identified until later in pregnancy, thus potentially diminishing the quality of obstetric care for pregnant individuals and possibly limiting their reproductive options, including pregnancy termination.

Completion of Fetal Anatomy Evaluations in Women With Body Mass Index ≥ 50 kg/m2

OBJECTIVES

As maternal body mass index (BMI) increases, fetal anatomy ultrasound becomes more challenging, less sensitive, and less likely to be complete. We sought to report our experience of incomplete evaluation of anatomy in patients with BMI of 50 kg/m2 or greater.

METHODS

This is a retrospective cohort of singleton gestations in mothers with BMI of 50 kg/m2 or greater, undergoing anatomy evaluations between 2017 and 2021 at 9 maternal-fetal-medicine sites in Houston, TX. Patient variables and scan results were collected throughout pregnancy to provide a longitudinal assessment of the primary outcome, completion rate (percent of all scans which optimally captured 24 American Institute of Ultrasound in Medicine-recommended images). Secondary outcomes included the rate of optimal capture of each individual structure.

RESULTS

In total, 293 patients with BMI ≥50 kg/m2 were identified. Only 28% of initial scans were complete, but over the entire pregnancy, a complete anatomic evaluation was achieved in 76% of women, largely due to weekly ultrasounds done for antenatal testing later in pregnancy. Neither BMI, placental location, nor amniotic fluid volume affected completion rate. The most difficult views are the outflow tracts, 4-chamber view, and spine.

CONCLUSIONS

One quarter of women with BMI of 50 kg/m2 or greater will not have a complete fetal anatomic evaluation by the end of pregnancy, since even basic fetal anatomic views are technically challenging to complete. Solutions deserve further attention, and may include first trimester imaging, transvaginal imaging, and optimization of ultrasound machine settings.

First trimester anatomy ultrasound for patients with obesity: a randomized controlled trial

BACKGROUND

Second-trimester ultrasound is the standard technique for fetal anatomy evaluation in the United States despite international guidelines and literature that suggest that first-trimester timing may be superior in patients with obesity. First-trimester imaging performs well in cohorts of participants with obesity.

OBJECTIVE

Our aim was to compare the completion rate of a first-trimester fetal anatomy ultrasound scan with that of a second-trimester fetal anatomy ultrasound scan among pregnant people with a body mass index ≥35 kg/m2.

STUDY DESIGN

This randomized controlled trial enrolled participants with a body mass index ≥35 kg/m2 with a singleton gestation and who presented before 14+0/7 weeks of gestation. Participants were randomized to receive an ultrasound assessment of anatomy at either 12+0/7 to 13+6/7 weeks or at 18+0/7 to 22+6/7 weeks. The primary outcome was completion rate (percentage of scans that optimally imaged all the required fetal structures). Secondary outcomes included the necessity of a transvaginal approach, completion rates for each individual view, number of anomalies identified and missed in each group, scan duration, and patient perspectives. A 1-year pilot sample was analyzed using Bayesian methods for the primary outcome with a neutral prior and frequentist analyses for the remaining outcomes.

RESULTS

A total of 128 participants were enrolled, and 1 withdrew consent; 62 subjects underwent a first-trimester ultrasound scan and 62 underwent a second-trimester ultrasound scan. A total of 2 participants did not attend the research visits, and 1 sought termination of pregnancy. In the first-trimester group, 66% (41/62) of ultrasound scans were completed in comparison with 53% (33/62) in the second-trimester ultrasound group (Bayesian relative risk, 1.20; 95% credible interval, 0.91-1.73). When compared with a second-trimester scan plus a follow-up ultrasound, a first-trimester ultrasound plus a second-trimester ultrasound was equally successful in completing the anatomy views (76%). First-trimester anatomy ultrasound scans required a transvaginal approach in 63% (39/62) of cases and had a longer duration than a second-trimester ultrasound scan. No anomalies were missed in either group. First-trimester ultrasound participants who responded to a survey described that they were very satisfied with the technique.

CONCLUSION

In pregnant subjects with a body mass index ≥35 kg/m2, a single first-trimester anatomy ultrasound scan was more likely to obtain all the recommended anatomic views than a single second-trimester ultrasound scan. An evaluation of anatomy at 12+0/7 to 13+6/7 weeks' gestation plus an evaluation at 18+0/7 to 22+6/7 led to complete anatomic evaluation 4 weeks earlier than 2 second trimester scans. Assessment of ultrasound duration in a clinical setting is needed to ensure feasibility outside of a research setting.

Novelties of ultrasound imaging for endometrial cancer preoperative workup

INTRODUCTION

Endometrial cancer (EC) is the most frequent gynecological cancer. Transvaginal ultrasound (TVU) plays a leading role in the preoperative workup and often is the first diagnostic instrumental examination. Despite expert hands' ultrasound is recommended to assess myometrial invasion in early stage EC, this method is a strictly operator-dependent examination, and varying degrees of sensitivity and specificity have been reported. The present review aims to provide an update of ultrasound imaging in the preoperative work-up for EC patients.

EVIDENCE ACQUISITION

A double-blind search was performed from May to September 2020. The following keywords: "ultrasound," "transvaginal ultrasound" and "endometrial cancer" were searched in Pubmed search engines, Scopus, and Web of Science. The Prisma statement was followed for the selection of the articles included.

EVIDENCE SYNTHESIS

The initial search provided 958 studies, of which 11 were included in the analysis. non-English articles, not relevant to the purposes of this study, case reports and articles with fewer than 40 cases were excluded.

CONCLUSIONS

TVU sensitivity and specificity in myometrial infiltration and cervical invasion is comparable to MRI but has lower costs, greater patient tolerability, and does not require contrast agents. An expert operator should perform the ultrasound examination in patients with suspected EC The presence of myometrial lesions, such as leiomyomas, could lower the diagnostic accuracy of ultrasound, so special attention should be paid to patients with concomitant uterine lesions.

Delay of Fetal Anatomy Ultrasound Assessment Based on Maternal Body Mass Index Does Not Reduce the Rate of Inadequate Visualization

OBJECTIVES

To determine whether delay of initial anatomy ultrasound based on the maternal body mass index (BMI) reduces the rate of inadequate visualization compared to standard timing at 18^0/7 to 19^6/7 weeks.

METHODS

A retrospective study of singleton anatomy assessments was conducted at a tertiary care center in the 2-year period before (A, 2012-2014) and after (B, 2014-2016) protocol initiation. Assessments in period B were scheduled on the basis of the BMI in the first trimester: lower than 25 kg/m² , 18^0/7 to 19^6/7 weeks; 25 to 29.9 kg/m² , 19^0/7 to 20^6/7 weeks; 30 to 34.9 kg/m² , 20^0/7 to 21^6/7 weeks; 35 to 39.9 kg/m² , 21^0/7 to 22^6/7 weeks; and 40 kg/m² or higher, 22^0/7 to 23^6/7 weeks. In period A, assessments were scheduled between 18^0/7 and 19^6/7 weeks. The rate of inadequate visualization and repeated assessments in periods A and B were compared. Multivariable logistic regression, per-protocol, and BMI subgroup analyses were completed.

RESULTS

In total, 3491 pregnancies in period A and 3672 in period B were included. In period B, 74% were scheduled per protocol; however, this rate decreased for higher-BMI categories (52% for BMI ≥40 kg/m² ). The inadequate visualization rate was slightly higher in period B versus A (16.9% versus 15.0%; P = .03) and exceeded 35% for a BMI of 40 kg/m² or higher, with or without delay. After adjusting for maternal age and fetal presentation, period B had small increased odds of inadequate visualization versus period A (adjusted odds ratio, 1.2; 95% confidence interval, 1.02-1.38). Repeated assessment rates were similar in periods B and A (14.0% versus 13.1%; P = .25).

CONCLUSIONS

In pregnancies with obesity, a protocol delaying the initial assessment beyond 19^6/7 weeks based on the maternal BMI does not reduce the rate of inadequate visualization.